[RE-wrenches] L feet no flashing in shingle roof

[Solarguy]

The text doesn’t imply that the wood will not split, it simply says it can be driven in without a pilot hole. For that matter a sheet metal screw can be driven into wood without a pilot hole.

The reason that the pilot hole offers an advantage is because there will be threads cut into the entire 360° contact surface of the hole. Without a pilot, the wood will split along the grain, maybe only a tiny amount but the laws of physics make no exception because of an advertised claim. Where there is no metal to wood contact there is no holding power and the pullout strength is compromised. But that’s why the pullout charts use a 2x safety factor. 

Dave B. said it clearly, “I'm not sure why anyone would knowingly expose themselves to a possible construction negligence claim.”.

My 2¢ 2x

 

Jim Duncan

North Texas Renewable Energy Inc

www.ntrei.com <http://www.ntrei.com/>  

NABCEP PV 031310-57

TECL-27398

ntrei at 1scom.net 

817.917.0527

 

 

 

From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Benn At DayStarSolar
Sent: Tuesday, July 03, 2012 5:36 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] L feet no flashing in shingle roof

 

I haven't read up on the mentioned structural screws yet, but do they specifically state that they can be driven "without" a pilot hole?  What is the justification and how are they different so that they won't cause a board to split under pressure?

Does anyone have some good info on this?

benn

Sent from a 'smart' phone, with tiny keys. Please excuse shortcuts and typos. 





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